Sight for trench excavators



D. F. PRZYBYLSKI '2,580;954

SIGHT FOR TRENCH EXCAVATOR Jan. 1, 1952 3 Sheets-Sheet 1 Filed March 28, 1949 1952 l D. F. PRZIYBYLSKI 2,580,954 SIGHT FOR TRENCH EXCAVATOR Filed March 28, 1949 7 a Sheets-Sheet 2 lnvenj'or pan/e 1W 2M Jan. 1, 1952 Filed March 28,

D. F. PRZYBYLSKI 2,580,954

SIGHT FOR TRENCH EXCAVATOR '5 Sheets-Shet 5 haw/17 Patented Jan. 1, 1952 oF icE v v 2,580,954 SIGHT FOR TEEN CH EXCAVATORS Daniel Pr zybylski, Winona, vMinn. Application March 28, 1949, Serial No. 83,916- 1 Claim. '(01. ss 1s5-) My present invention relates to improvements insights and, more particularly, to asight for use in connection with a trench excavator.

While this invention is intended for general use in connection with machines that operate to an established grade, it is especially designed for use in connection with my improved trench excavator disclosed and broadly claimed in my. pending United States application filed September '7, 1948, under Serial Number 48,121.. V

The object of this invention is to permit the operator of a trench excavator to keep the boom of said excavator, which carries the shovels that travel an endless course, in a position in which the shovels dig to an established grade for the bottom of the trench being dug according to stakes set by a surveyor.

To the above end, the invention consists of the novel devices and combination of devices hereinafter described and defined in the claim.

In the accompanying drawings, which illustrate the invention, like characters indicate like parts throughout the several views.

Referring to the drawings:

Fig. 1 is a side elevational view of a trench excavator of the full track type having the invention embodied therein and also showing two grade stakes;

Fig. 2 is a fragmentary detail view of one of the grade stakes, on an enlarged scale, and looking at the same from the line 2-2 of Fig. 1;

Fig. 3 is a side elevational view of the improved sight and a fragment of the boom structure to which the sight is secured, on an enlarged scale,

some parts of the sight being broken away and other parts sectioned;

Fig. 4 is a front end view of the sight frame, as shown in Fig. 3;

Fig. 5 is a fragmentary plan view of the sight frame, as shown in Fig. 3;

Fig. 6 is a view principally in elevation, with some parts sectioned on the line 66 of Fig. 1, and with other parts shown in a different position by means of broken lines, on the same scale as Fig. 3; and

Fig. '7 is a fragmentary view partly in elevation and partly in section on a greatly enlarged scale.

For the purpose of showing the improved sight in working position, there is shown in Fig. 1 a

trench excavator of the full track type shown 5,;

in the application heretofore referred to. This trench excavator is indicated as an entirety by the numeral 8, with the exception of the boom 9, the shovels I carried by a driven endless chain 1] on said boom, the upstanding frame I2 and the seat I3 for an operator at for the trench excavator.-

The seat I3 is located at one side of the trench excavator 8 so that the operator .2: has a clear vision rearward of said excavator and the work being performed thereby.

The improved sight. is carried by the boom 9 and has a skeleton frame that includes a pair of laterally spaced side sections I4, each in the form of a right-angled triangle. Onev of: the rightangle members I of each side. section is relatively short and verticall disposed, while the other right' angle. member is is relatively long and horizontally disposed. The oblique :member ll of each side section It which is the hypotenuse of the triangle, is under the member I6.

The apexes of the side sections I4 point rearwardly relative to the trench excavator 8 and the side sections I4 are secured to the frame I2 at the lower end portions of the vertically disposed members I5, as indicated at I8. Each side section I4 is further secured to the frame I2 by a flat brace bar I9. The top members I 6 of the two side sections I4 are rigidly connected by front, rear and intermediate cross-tie channel bars 28, 2I, and 22, respectively, and positioned with their flanges horizontally disposed. The members I5, l6 and I7 of the side sections I4 are angle bars and the members I6 and ll of each side section I4 are intermediately connected by upright angle bars 23. The members I5 and the front channel bar 2| are rigidly connected by webs 24.

The sight is suspended from the rear channel bar 2| and includes a pendulum bar 26 attached, at its upper end, to said channel bar by a coupling 21 for compound swinging movement longitudinally and transversely of the trench excavator 8. This coupling 21 includes a head 28 rigidly secured to the pendulum bar 26, at its upper end portion, and has a pair of upstanding ears 2!! laterall spaced transversely of the trench excavator 8. A short link extends between the ears 29 and is pivoted thereto. This link 30 also extends between a pair of depending ears 3| on the lower flange of the channel bar 2I and pivoted thereto for swinging movement transversely of the trench excavator 8. On the lower end of the pendulum bar 26 is a pendulum weight 32.

An assembly mount, in the form of along horizontal tubular bar 33, is rigidly secured,at its longitudinal center, to the pendulum bar 26 near its upper end and extends transversely of the trench excavator. A mount 34 for a tubular sight bar 35 is mounted on the end section of the tubular bar 33 that projects from the said side of the trench excavator on which the seat I3 is located. This mount 34 includes a sleeve 36 slidably mounted on the bar 33 and secured where adjusted thereon by a hand screw 31 having threaded engagement with the sleeve 36 and iminging the bar 33. The hand screw 31 is provided with a lock nut 38. The mount 34 further includes a vertical sleeve 39 in which the sight bar 35 is slidably mounted and is held where adjusted in said sleeve by a hand screw 40 having threaded engagement with said sleeve and impinging the sight bar 35. This hand screw 40 is provided with a lock nut 41. The sight bar 35 is provided at one end with a T-head 42. The sight bar 35 is mounted in the sleeve 39 for endwise reversal so as to position the T-head 42 above the bar 33, as shown by full lines in Fig. 6, or below said bar, as shown by broken lines. A balancing weight 43 is slidably mounted on the opposite end portion of the bar 33 from the mount 34.

Rearwardly of the trench excavator 8 are two grade stakes 45, each having a T-head 46 with which the T-head 42 of the sight is aligned. The T-head 42 on the sight 25 is kept aligned with the T-heads 46 on the grade stake by raising or lowering the boom 9 to control the depth at which a trench is dug by the shovels 10..

The drawings illustrate a commercial form of the invention, but it will be understood that the same is capable of certain modifications as to details of construction, arrangement and combination of parts within the scope of the invention herein disclosed.

What I claim is: g

A pair of laterally spaced side frames applicable in fixed positions to the sides of the shovel carrying boom of a trench excavator, each side frame being formed of bars in right-angle triangle arrangement, one bar of the right-angle being upright and the other bar thereof extending rearwardly from the top or the upright bar, a crosstie bar connecting the'two side frames at their outer ends above the boom, a pendulum attached to the cross-tie bar at the intermediate portion for swinging movement both longitudinally and transversely of the boom, and a sight including a horizontal member above and outwardly of one of the side frames and mounted on the pendulum for adjustment both vertical and horizontal.

DANIEL F. PRZYBYLSKI.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Reising NOV. 22, 1949 

